FilterMAG SS365PR SS FilterMag Fits 3.50"-4.00" diameter Height: 2.25"

Works, i.e. it’s effective. I’ve purchased 2 oil filter can opener tools for opening spin-on oil filters (thru JEGS). Race teams and pilots need to know what their engine is “up to”. Since engines can’t talk, you can’t ask them. So, you must cut the old filter open, after an oil change. Since i’ve had my FilterMags, i can see the results, and know. Not think about it, but really actually know. Data-driven decisions! Back to the point; these magnet arrays really do work. They won’t catch everything; only the ferritic contaminants. The hybrid semi-synthetic fiberglass/paper filter element in my Bosch “Distance-Plus” oil filter, catches the non-ferritic particulates, down to 20-microns. Avoid cheapie filters (paper-only media is only good down to 30-microns). Most engine wear is from what even the best “flow-thru” filters cannot catch; in the 2 to 20-micron range. That’s where FilterMag products come-in. They get all the small stuff. Clearly evident upon inspecting the inner can wall, where the FilterMag was, before moving it to the new filter at OCI. Seeing, is believing. Believe me, it is obvious. Currently have 291,000 miles on my original 1995 Mercury Grand Marquis 4.6L V8, and its OHC valvetrain is still going strong on the original timing chains, sprockets, chain guides, and hydraulic tensioners. I definitely reccomend FilterMag products. They are even better than the small single washer-style neodymium magnet I used to use (but was better than nothing). If you don’t use or cannot fit a secondary “bypass” oil filter, like big-rigs use, then this is the next best thing. No matter your main filter brand/media, FilterMag units provide coverage from 30-microns, down to 2-microns for containment of the iron wear particles, suspended in your dirty motor oil. Happy travels!

Stays in place, won't budget from vibrations or heat. Not sure how effective but can't hurt. Magnets incredibly strong so if they use the same principle for magnetic drain plugs why couldn't this be helpful in the longterm. Set and forget, reusable.

very good

Video going over what I think of the products from opening it to also inspecting the strength of the magnets on a oil filter.

Perfect fit on my large 7.3 liter diesel filters.

very effective.

The FILTERMAG SS365PR fits the 4.6-liter FOMOCO (Ford, Lincoln, Mercury) engine's FL-820S oil filter perfectly. Easy install, no moving parts, lasts a lifetime. Massive 11.4 square inches of full magnetic power to remove ferrous metal particles of ALL sizes. Specially treated to function perfectly at temps from -40 F. to +300 F, while other magnets are NOT CAPABLE of handling high oil temperatures. Unfortunately, Amazon's price is WAY TOO HIGH !!

I was sold on these after seeing an engine come in for a rebuild that had a flat tappet lifter failure. It was a twin engine boat, supercharged mercruiser, big block chevy. The lifter and cam lobe were destroyed. Normally when I saw engine with this failure a bunch of metal makes it way into the filter, through the bypass valve, and damages bearings, crankshaft, and so on. This engine was equipped with the filter mag. There was ZERO damage to main bearings or crankshaft even after running with the failing flat tappet lifter and camshaft.